Collar coupled plastic conduit

Abstract

A plastic conduit for protecting and directing electrical and telephone cables, employing elongated barrel portions with lipped ends and a snap-on coupling collar. Partition walls intergral with the conduit walls are used to divide the internal passageway of the conduit section. The partition walls are contoured at each end to interlock with the ends of adjacent conduit sections to provide column-like support. Gasketed ends seal the joint between the conduit section and coupling collar. Flanged ends index the coupling collar and limit axial movement and deflection. Interrupted peripheral lips and an interrupted annulus within the coupling collar provide for differential flaring out of the collar ends and corresponding necking-in of the conduit ends as the two are telescoped together. The lipped edges are received within the annulus of the coupling collar and snap fit into position. The snap fitting lips lock the conduit section to the coupling collar. The coupling collar is reinforced within external ribs and has camming surfaces at each end to assist snap fitting the coupling collar onto the conduit ends.

I claim: 
     
       1. A plastic conduit section for connection to similar conduit sections, comprising: a plurality of interconnected enclosing walls defining an open ended conduit passageway with end portions having on their outside surfaces a peripheral, circumferential groove adjacent the free ends, and a circumferential flange adjacent said groove; a resilient conduit coupling collar having a plurality of parallel interconnected walls at least at one of its ends defining an open ended closure with said collar walls having inner transverse dimensions generally equal to the outer transverse dimensions of the outside surfaces of said end portions adjacent said grooves, said collar having a length sufficient to telescope upon and join together the end portions of two adjacent conduit sections; a gasket carried within each of said grooves to seal the joints between the exterior of said conduit end portions and the interior of a coupling collar telescoped over that end portion; and means, integral with and adjacent said end portions and cooperating with the interior surfaces of said coupling collar, for mechanically locking said two adjacent conduit sections and said coupling collar together by snap fitting action and said grooves being located intermediate said flange and said means. 
     
     
       2. A plastic conduit section as defined in claim 1, wherein said means for mechanically locking includes: conduit passageway end portions having a peripheral, outward extending, circumferential, generally continuous raised lip with the outer transverse dimensions of said lip being generally greater than the outer transverse dimensions of the outside surfaces of said end portions adjacent of said groove, and with the leading edge said lip being beveled to a smooth edge to allow inward necking of said conduit passageway end portions; and a coupling collar having at its interior an annular adapted to receive said lip, the inner transverse dimensions of the inside surfaces of said collar adjacent said annulus being generally equal to outer transverse dimensions of said lip, whereby a snap fit is obtained by interposing said collar over the end portions of said two adjacent conduit sections when said lip is received in said annulus, said collar holding together two adjacent conduit sections in a unitary structure. 
     
     
       3. A plastic conduit section for connection to similar conduit sections, comprising: a plurality of interconnected enclosing walls defining an open ended conduit passageway with end portions having on their outside surfaces a peripheral, circumferential groove adjacent the free ends, and a circumferential flange adjacent said groove; a resilient conduit coupling collar having a plurality of parallel interconnected walls at least at one of its ends defining an open ended closure with said collar walls having inner transverse dimensions generally equal to the outer transverse dimensions of the outside surfaces of said end portions adjacent said groove, said collar having a length sufficient to telescope upon and join together the end portions of two adjacent conduit sections; a gasket carried within each of said the grooves to seal the joints between the exterior of said conduit end portions and the interior of a coupling collar telescoped over that end portion; and means, adjacent said end portions and cooperating with the interior surfaces of said coupling collar, for mechanically locking said two adjacent conduit sections and said coupling collar together by snap fitting action, said mechanical locking means including: conduit passageway end portions having a peripheral, outward extending, circumferential, raised lip whose outer transverse dimensions are generally greater than the outer transverse dimensions of the outside surfaces of said end portions adjacent said groove, whose leading edge is bevelled to a smooth edge to allow inward necking of said conduit passageway end portions, and whose trailing edge is at right angles to said enclosing walls; and   said resilient coupling collar having an interior annulus adapted to receive said lip said annulus having inner transverse dimensions generally equal to the outer transverse dimensions of said lip and a generally rectangular cross section,   whereby a snap fit is obtained by interposing said collar over the ends of said two adjacent conduit sections when said lip is received in said annulus, the annulus and lip forming interlocking complementary surfaces locking the two conduit sections to the collar.   
     
     
       4. A plastic conduit section as defined in claim 2, wherein said coupling collar has bevelled inside edges to cause said lip to neck inwardly and said collar ends to flare outwardly relative to each other by the camming action between the bevelled leading edge on said lip and the bevelled inside edge on said collar. 
     
     
       5. A plastic conduit section as defined in claim 3, wherein said annulus and said lip are interrupted at least at one location along their circumference with the interruptions in said annulus corresponding to and complementary with the interruptions on said lip portions to thereby reduce the force required to snap fit said collar on said conduit end portions. 
     
     
       6. A plastic conduit section as defined in claim 3, wherein said coupling collar is reinforced by an equitorial circumferential rib and by a plurality of longitudinal ribs on the outside periphery of said coupling collar, said longitudinal ribs being generally at right angles to and contiguous with said equitorial rib, the outer dimensions of said ribs being greater than the outer dimensions of said enclosing walls, whereby the end portions of said conduit passageway are forced to neck inwardly when said coupling collar is telescoped over said end portions while maintaining the thickness of said coupling collar generally equal to the thickness of said conduit enclosing walls. 
     
     
       7. A plastic conduit section for connection to similar conduit sections, comprising: a conduit having a plurality of interconnected enclosing walls defining an open ended, elongated, smooth surfaced enclosure with said enclosing walls having integral to them a plurality of partition walls dividing the interior of said enclosure into a plurality of elongated passageways, said enclosing walls having at their ends a circumferential, peripheral, outwardly disposed groove, said enclosing walls having a circumferential flange adjacent each of said grooves, said grooves separating said flanges from the ends of said enclosing walls; a resilient conduit coupling collar, adjacent one of the ends of said conduit enclosing walls, having a least at one of its ends a plurality of parallel interconnected enclosing walls defining an open ended enclosure with said collar walls having inner transverse dimensions generally equal to the outer transverse dimensions of the outside surfaces of said end portions adjacent said grooves and having a length sufficient to receive two adjacent conduit sections that have been telescoped into said coupling collar; gasket means, carried within each of said grooves, for sealing the joints between the exterior of said conduit and the interior of a coupling collar telescoped over that end portion; and mechanical means closer to each end of said conduit than said grooves cooperating with the interior of a coupling collar, for mechanically locking together two adjacent conduits to said coupling collar by snap fitting action. 
     
     
       8. A conduit section as defined in claim 6, wherein said mechanical means includes: conduit end portions having a circumferential lip interrupted at least at one location along its perimeter, said lip having a perimeter generally equal to the exterior perimeter of said conduit enclosing walls, and a coupling collar having an interior annulus dimensioned to receive said lip, whereby a snap fit is obtained by interposing said coupling collar over the ends of said two conduit sections when said lip is received in said annulus, said snap fit holding said conduit sections and said collar in a unitary structure. 
     
     
       9. A plastic conduit section as defined in claim 7, wherein said means for mechanically locking includes: conduit end portions with a peripheral, outward extending, circumferential lip, and with the leading edge of said lip bevelled to a smooth edge; and a coupling collar having an interior, central annulus to receive said lip, whereby a snap fit is obtained by interposing said collar over the ends of said conduit sections when said lip is received in said annulus thereby holding said conduit sections and said collar into a unitary structure. 
     
     
       10. A conduit section as defined in claim 9, wherein said annulus is interrupted to allow outward flaring of said collar when said lip is telescoped on said collar. 
     
     
       11. A plastic conduit section for connection to similar conduit sections, comprising: a conduit having a plurality of interconnected enclosing walls defining an open ended, elongated, smooth surfaced enclosure with said enclosing walls having integral to them a plurality of partition walls dividing the interior of said enclosure into a plurality of elongated passageways, said conduit having on its exterior surface a circumferential, peripheral groove adjacent each of its two ends and having on its exterior surface a circumferential flange adjacent said groove, said groove separating said flange from the adjacent end of said conduit; a resilient conduit coupling collar adjacent one of the ends of said conduit having a plurality of parallel interconnected enclosing walls at least at one of its ends defining an open ended enclosure with said collar walls having inner transverse dimensions generally equal to the outer transverse dimensions of the outside surfaces of said conduit adjacent said grooves, and having a length sufficient to receive the ends of two adjacent conduits that have been telescoped into said coupling collar; a gasket carried within at least one of said grooves to seal the joint between the outside surfaces of said conduit and said coupling collar; and mechanical means for mechanically locking together two adjacent conduits to said coupling collar by snap fitting action, said mechanical means including: conduit end portions with a peripheral, interrupted, outward extending, circumferential lip, said lip having interruptions to each side of the orthogonal centers of said conduit walls to allow necking-in of said lip, with the outer transverse dimensions of said lip being generally greater than the outer transverse dimensions of said groove but generally less than the outer transverse dimensions of said flange, the leading edge of said lip being bevelled to a smooth edge and the trailing edge of said lip being generally at right angles to the exterior surfaces of said conduit enclosing walls; and said coupling collar having an interior, central, generally rectangular, interrupted annulus to receive said lip, the interruptions in said annulus being to each side of the orthogonal centers of said collar enclosing walls and complementary to the interruptions in said lip,   whereby a snap fit is obtained by interposing said collar over the ends of said two conduit sections when said lip is received in said annulus, the trailing edges of said lip cooperating with the inner edges of said annulus to hold said conduit sections and said collar in a unitary structure.   
     
     
       12. A plastic conduit section as defined in claim 11, wherein said coupling collar is reinforced by an equitorial rib and a plurality of longitudinal ribs on the periphery of said collar at right angles to said equitorial rib. 
     
     
       13. A conduit section comprising: a conduit having a plurality of interconnected enclosing walls defining an open ended, elongated, smooth surface enclosure with said enclosing walls having integral to them a plurality of partition walls dividing the interior of said enclosure into a plurality of elongated passageways, said enclosing walls having on their outside surface a circumferential, peripheral groove adjacent at least one of its ends and a circumferential flange adjacent each of said grooves; a resilient conduit coupling collar adjacent said one end and having a plurality of parallel interconnected enclosing walls at least at one of its ends defining an open ended enclosure with said collar enclosing walls having an inner transverse dimension generally equal to the outer transverse dimension of the outside surfaces of said conduit adjacent said groove, said collar having a length sufficient to receive two similar adjacent conduit sections that have been telescoped into the ends of said coupling collar; a gasket carried within that groove adjacent said one end to seal the joint between said conduit and said coupling collar; and mechanical means, at the ends of the flanged enclosing walls and at the interior of said coupling collar, for mechanically locking said conduit to said coupling collar into a unitary structure by snap fitting action, said mechanical means including: conduit end portions having at said one end a peripheral, outward extending, circumferential lip whose leading edge is bevelled to a smooth edge and whose trailing edge is at right angles to the exterior surfaces of said conduit walls; and   said coupling collar having an interior, central annulus to receive said lip, the annulus of said collar being generally rectangular in cross-section, whereby the trailing edge of said lip and the interior side walls of said annulus interlock together when said lip snaps back into its original shape, said lip having been forced to neck inwardly when passing into said coupling collar.   
     
     
       14. A resilient plastic coupling collar for joining together two adjacent similar conduits, said conduits having lipped end portions at the terminal ends of said conduits and a sealing gasket positioned adjacent said lipped ends, comprising: a plurality of parallel interconnected walls at least at one of its ends defining an open ended enclosure to telescope upon two adjacent conduits, the inside surface of said collar walls mating with the outside of a sealing gasket carried on said conduit sections; said interconnected walls defining an interior circumferential cavity to receive the lipped ends of said conduits, whereby a snap fit is obtained by interposing said collar over the ends of said conduits, the outer transverse dimensions of said lipped ends being generally greater than the inner transverse dimensions of the ends of said collar and generally less than the outer transverse dimensions of said cavity, said lipped ends and said cavity cooperating to hold together said two conduits and collar in a unitary structure, the inside edges of said interconnected walls being bevelled to a smooth surface thus forming a camming surface to neck inwardly the lipped edges of said conduits and to flare outwardly the ends of said collar when said collar is telescoped upon said conduit ends.   
     
     
       15. A coupling collar as defined in claim 14, wherein said interior cavity is an interrupted annulus. 
     
     
       16. A plastic conduit section for connection to similar conduit sections, comprising: a conduit having a plurality of interconnected enclosing walls defining an open ended passageway; a plastic conduit coupling collar, adjacent one of the free ends of said conduit section, having at least on its ends a plurality of interconnected parallel walls defining an open ended enclosure, the walls of said collar having inner transverse dimensions generally equal to the outer transverse dimensions of said conduit sections so as to telescope upon and join together two adjacent similar conduit sections; sealing means, on the ends of said conduit section, for sealing the joint between said conduit section and said coupling collar; and circumferential means, adjacent the ends of said conduit sections and at the interior of said collar, for mechanically locking together said two adjacent similar conduit sections to said coupling collar by snap fitting action, said conduit sections having a circumferential flange adjacent said sealing means, said sealing means being located intermediate said flange and said circumferential means said flange acting as a stop to limit the travel of said collar along the free ends of said conduit, whereby said two adjacent conduit sections are coupled together by driving the ends of said conduit sections into the interior of said collar, said collar being correctly positioned to accept each of said conduit sections by virtue of said flange. 
     
     
       17. A plastic conduit section for connection to similar conduit sections by a coupling collar which overlaps the ends of each conduit section, comprising: a plurality of interconnected enclosing walls defining an open-ended passageway with end portions having a peripheral flange; said end portions adapted to receive said coupling collar for joining together the end portions of two adjacent similar conduit sections; a sealing surface on the exterior surface of said end portions to seal the joint between one of said conduit end portions and said coupling collar; stop means adjacent said flange for limiting the travel of the coupling collar along said end portions, said sealing surface lying between said flange and said stop means; and means on said collar and flange for mechanically locking the end portions of said enclosing walls to said collar by snap-fitting action, whereby said coupling collar is correctly positioned along the end portions of said enclosing walls by driving said coupling collar on said end portions until said stop means is engaged, said mechanical means holding said coupling collar intermediate the end portions of said two conduit sections in sealing engagement with said two conduit sections.